Shoe Parts

Two types of dress shoes are commonly worn: the Blucher and the Bal (Figure 15-1). The tongue is part of the vamp in the Blucher shoe. The quarters overlap the vamp. A Blucher shoe is recommended for patients requiring an orthosis because there is more room to don and doff the shoe and the orthosis because of the open throat.⁶³ In the Bal shoe style the quarters meet at the throat. The vamp is stitched over the quarters at the throat, thereby limiting the ability of the shoe to open and accommodate an orthosis.

FIGURE 15-1 Shoe types and components. The open throat of the Blucher shoe accommodates an orthosis better than the Bal shoe.

Common Foot Conditions

Forefoot Pain (Metatarsalgia)

Relief of pain in the forefoot is accomplished by distributing the weight-bearing forces to an area proximal to the metatarsal heads. This can be done by either internal or external modification. A metatarsal pad (also referred to as a “cookie”) can be placed inside the shoe just proximal to the second, third, and fourth metatarsal heads. It should also be just proximal to the lateral aspect of the first metatarsal head and medial to the fifth metatarsal head (Figure 15-3). A metatarsal bar is recommended for cases in which the foot is too sensitive to tolerate a pad inside the shoe. The metatarsal bar is typically ¼-inch thick and tapers distally. The distal edge should be proximal to the metatarsal heads. It is often applied to a leather or neoprene sole.³⁵ The metatarsal bar can also be used for forefoot pain associated with pes cavus. A rocker bottom (Figure 15-4) can also be used for metatarsalgia to decrease the force on the metatarsal pad region at push off.

FIGURE 15-3 Metatarsal pad for forefoot pain. This should be placed proximal to the metatarsal heads to reduce weight distribution on the metatarsal heads.

FIGURE 15-4 (A) A spring coil in this shoe located at the anterior heel can alleviate heel pain by moving the ground reaction force anterior to the painful portion of the calcaneus in addition to lessening impact at heel strike. This can help with knee stability also. The forefoot is also designed as a rocker bottom for forefoot comfort. (Courtesy Z-CoiL Footwear, Albuquerque, NM.)

(B) Rocker bottom shoe. This is prescribed for patients with ankle fusions to help normalize their gait pattern by simulating plantar flexion. A rocker bottom can also be prescribed for heel pain because it helps move the contact point at heel strike anterior to the painful calcaneus. Hence, the ground reaction force is also moved anterior to the painful heel. For metatarsalgia it decreases force across the metatarsal heads at push off. This type of shoe can now be purchased in some shoe stores in addition to being custom built into an existing regular pair of shoes.

Prevention of forefoot pain should also be emphasized to patients. Patients should avoid shoes with high heels or pointed toes, which place excess stress on the metatarsal heads.⁴

Heel Pain

The painful area can be alleviated by using an orthosis to help distribute weight. Rubber heel pads can be applied inside the shoe to offer relief in cases of minor discomfort. A calcaneal bar is recommended for cases in which the foot is too sensitive to tolerate a pad inside the shoe and the heel pain is associated with a chronic condition. The calcaneal bar is placed distal to the painful area to prevent the calcaneus from assuming full weight-bearing status. The same can be accomplished with a shoe that has a spring for the heel set on the anterior calcaneus (see Figure 15-4, A). The application of a rocker bottom shoe can also be used to help initiate heel strike anterior and the ground reaction force anterior to the painful calcaneus (see Figure 15-4, B). Both of these shoe types are now commercially available.

A common cause of heel pain along the anteromedial calcaneus is plantar fasciitis. Pain occurs at the attachment site of the fascia along the medial aspect of the heel.³⁹ Point tenderness is located over the anteromedial calcaneus. It is common in people who hyperpronate their feet, thereby placing excess stress on the medial longitudinal arch. A custom-made orthosis with the subtalar joint in a neutral position (such as that described for pes planus) helps prevent excessive inrolling from occurring and reduces the stress placed along the proximal arch. A custom-made UCB orthosis is indicated for cases in which conservative treatment has failed. From an orthotic standpoint, conservative treatment should include the use of a pair of shoes with a firm medial heel counter and a wide shank (see Figure 15-1).

An additional orthotic intervention for plantar fasciitis is the application of a plantar fascia night splint, which is a prefabricated AFO placed in a few degrees of dorsiflexion.^16,42 This helps provide the plantar fascia and plantar flexors a therapeutic stretch during sleep hours, assuring the patient several hours of passive stretching daily. Such a device is recommended for as long as is necessary until the patient is asymptomatic (Figure 15-5).

FIGURE 15-5 Plantar fascia night splint. This prefabricated AFO provides a therapeutic stretch to the plantar fascia and plantar flexors nightly to help alleviate anteromedial heel pain and facilitate a recovery.

(Courtesy BREG, Inc, Vista, Calif and Elizur Corp, Pittsburgh, PA.)

Plantar fasciitis is also common in patients with high arches. For these patients the medial longitudinal arch undergoes marked stress during weight-bearing. This can be treated with either an elevated arch support or a heel well that helps distribute pressure along the medial longitudinal arch.

Heel spurs are frequently mistaken as the source of heel pain. Heel spurs related to plantar fasciitis are the result of mechanical stress acting through the plantar fascia onto its origin at the calcaneus and are not the source of the pain.³⁴ Inferior heel spurs are related to advancing age and are not painful in nature.

Heel lifts help some causes of Achilles pain by decreasing the amount of stretch placed on the Achilles tendon (by keeping the ankle joint plantar flexed). A heel lift can be used to treat the pain associated with Achilles enthesitis, an inflammatory reaction at the insertion of the tendon into the periosteum of the calcaneus. For Achilles enthesitis, a heel lift is meant to be used for weeks—not months—to prevent the development of a plantar flexion contracture. A heel lift can also be helpful for treating plantar flexion spasticity or contracture by increasing the total heel height to help ensure that the patient has a heel strike before toe touch during gait.

Metal Ankle-Foot Orthoses

Metal AFOs are now used much less commonly than the plastic type. They will be discussed for the following four reasons:

Recent research has offered support that metal AFOs provide better stabilization of the ankle during the gait cycle.⁸

The metal AFO consists of a proximal calf band, two uprights, ankle joints, and an attachment to the shoe to anchor the AFO (Figure 15-6). The posterior metal portion of the calf band should be 1.5 to 3 inches wide to adequately distribute pressure.¹¹ The calf band should be 1 inch below the fibular neck to prevent a compressive common peroneal nerve palsy. A leather strap with Velcro is used to close the calf band, because it provides ease of closure for patients with only one functional upper limb.

FIGURE 15-6 Metal double-upright dorsiflexion assist AFO on right shoe with lateral T strap for control of varus deformity. The metal dorsiflexion assist ankle joint has also been referred to in the distant past as a Klenzak ankle joint. Note the split stirrup in the heel that allows the wearing of the orthosis with other shoes.

Ankle joint motion is controlled by pins or springs inserted into channels (Figures 15-7 through 15-10). The pins are adjusted with a screwdriver to set the desired amount of plantar flexion and dorsiflexion. The spring is also adjusted with a screwdriver to provide the proper amount of tension necessary to aid motion at the ankle joint (used to assist dorsiflexion). Longer channels help prevent the spring mechanism from ″bottoming out” and provide for more precise control of ankle motion.

FIGURE 15-7 Double-action metal ankle joint with solid stirrup.

FIGURE 15-8 Double-action stirrup (left) and dorsiflexion assist stirrup (right), used with the ankle joints shown in Figures 15-7 and 15-6, respectively.

(Courtesy USMC, Pasadena, CA.)

FIGURE 15-9 Split stirrup. The stirrup extends anteriorly to attach at the shank area of a shoe for stability. This stirrup is for dorsiflexion assist.

FIGURE 15-10 Schematic drawing of metal ankle joint components. This type of ankle joint is most commonly referred to as a double-action ankle joint. It has also been referred to in the distant past as a double Klenzak ankle joint or a BiCAAL (bichannel adjustable ankle locking) joint.

(Courtesy USMC, Pasadena, CA.)

A solid stirrup is a U-shaped metal piece permanently attached to the shoe. Its two ends are bent upward to articulate with the medial and lateral ankle joints (see Figure 15-7). The proximal stirrup attachment sites are shaped to enforce the desired movements at the ankle joint (see Figure 15-8). The sole plate can be extended beyond the metatarsal head area for conditions requiring a longer lever arm for better control of plantar flexion (e.g., plantar spasticity).

A split stirrup can be used instead of a solid stirrup (see Figures 15-6 and 15-9). The split stirrup has a sole plate with two flat channels for insertion of the uprights. The two uprights are now called calipers, as they can open and close distally to allow donning and doffing of the AFO. A split stirrup allows removal of the uprights from the shoes so that the AFO can be worn with other shoes (see Figure 15-6). Other pairs of shoes should also have the sole plate with channels for calipers incorporated into the heel area. The split stirrup is not as stable as the solid stirrup, and the metal uprights can pop out, which is the main reason a split stirrup is infrequently used.

Ankle Stops and Assists

The ankle joint can be positioned so that it is in a neutral, dorsiflexed, or plantar-flexed position, depending on the gait disturbance. It can be set to permit a partial range of motion or to eliminate a certain motion. An understanding of the effect on the placement of pins and screws into the two channels of an ankle joint (see Figure 15-10) facilitates the proper orthotic prescription for the patient. This section reviews the common uses of the posterior stop (via pin), anterior stop (via pin), and the posterior dorsiflexion assist (via spring) of the orthotic metal ankle joint (Table 15-1). A spring in the anterior channel has not been demonstrated to be of clinical value.

Table 15-1 Clinical Indications for Various Metal Ankle Channel Components

Plantar Stop (Posterior Stop)

The plantar stop is used to control plantar spasticity or help incrementally stretch plantar contractures. The plantar stop is most commonly set at 90 degrees. A pin is inserted into the posterior channel of an ankle joint, such as that in Figure 15-10, to limit plantar flexion. An AFO with a plantar stop at 90 degrees produces a flexion moment at the knee during heel strike. Because the dorsiflexors cannot eccentrically activate to permit the foot to make contact with the ground, the ground reactive force remains posterior to the knee after heel strike, which creates a flexion moment at the knee (and possibly an unstable gait via buckling). The proximal portion of the AFO also has an effect on knee stability. The posterior portion of the proximal AFO exerts a forward push on the proximal leg to increase the knee flexion moment after heel strike (Figure 15-11). The opposite occurs at toe-off, with an extension moment created at the knee. This concept has been used to develop what has been referred to as a plastic ground reaction AFO, with a solid proximal anterior tibial closing that provides a greater influence on the knee. This device will be discussed in more detail later. The greater the plantar flexion resistance, the greater the flexion moment at the knee at heel strike, and the greater the need for active hip extensors to prevent the body from collapsing forward on a buckling knee.

FIGURE 15-11 Ground reaction ankle-foot orthosis (AFO) dynamic illustration. Note the effect of the proximal portion of the AFO on the knee throughout gait.

(Courtesy Oregon Orthotic System, Albany, OR.)

Also, a solid ankle cushioned heel (SACH) heel wedge can be used to reduce the flexion moment at the knee. The term SACH is a misnomer borrowed from the prosthetic literature. The “SA” (solid ankle) refers to the type of prosthetic ankle joint. The SACH heel wedge in this case should be referred to only as a cushioned heel. A cushioned heel serves as a shock absorber at heel strike and is able to partially substitute for the dorsiflexors, which cannot be eccentrically activated when ankle plantar stops of an AFO are set at 90 degrees. A cushioned heel also helps move the ground reactive force more anteriorly at the foot and subsequently at the knee. In essence, a soft heel helps stabilize the knee. It helps keep the ground reaction force anterior to the knee joint. A firm heel decreases knee stability via a knee flexion moment while moving the ground reaction force posterior to the knee joint. A cushioned heel can also be used with an AFO to minimize the amount of plantar flexion spasticity present after heel strike. A firm heel can be used with an AFO for a patient with genu recurvatum.

The posterior stop should be set at the minimal amount of plantar flexion required to clear the foot during swing-through.¹⁸ Remember, plantar flexion creates a knee extension moment at the knee from midstance to toe-off. This provides a more stable knee during gait than when the ankle plantar stops are set in any degree of dorsiflexion.

A balanced decision should be made between providing resistance to plantar flexion to clear the foot during the swing phase of gait and the amount of instability at the knee during the stance phase of gait. No AFO is effective in reducing the amount of knee flexion to “normal” levels during the stance phase of gait.²⁰

Dorsiflexion Stop (Anterior Stop)

An anterior stop is used to substitute for the function of the gastrocnemius-soleus complex (Figure 15-12). It is used in conditions with weak calf muscles or weak quadriceps (because of its effect on the knee). Weak calf musculature allows the ankle to enter dorsiflexion, and dorsiflexion creates a knee flexion moment after heel strike. The anterior stop set at 5 degrees of dorsiflexion best substitutes for gastrocnemius-soleus function.^18,20 Three muscle groups help stabilize the knee during the gait cycle: the quadriceps, hamstrings, and gastrocnemius-soleus complex. All three of these muscle groups cross the knee joint and should be clinically evaluated and considered when prescribing a lower limb orthosis.

FIGURE 15-12 Schematic drawing of anterior pin stop simulating plantar flexion. (A) Anterior channels of ankle-foot orthosis component of a knee-ankle-foot orthosis left open in a spinal cord–injured patient. Note that the heel does not lift up (i.e., no plantar flexion). (B) Anterior channels of same orthosis with anterior pins in place set at 5 degrees of dorsiflexion and with metal sole plate. Note that the heel does lift up (i.e., plantar flexion) as momentum causes the lower limb to “pole-vault” over the anterior pin setting.

The anterior stop assists with push-off and assists the knee joint into extension. It should be used in combination with a stirrup with a sole extension to the metatarsal heads, to simulate the action of the calf muscles. The dorsiflexion stop simulates the gastrocnemius-soleus function by causing the heel to rise during the latter part of stance rather than remaining flat on the ground. The shoe pivots over the metatarsal heads, creating an extension moment at the knee that helps stabilize the knee from midstance to toe-off.

The earlier the dorsiflexion stop occurs during the stance phase, the greater the extension moment at the knee. This is useful in clinical situations where quadriceps weakness is also present. If the extension moment at the knee is too great for too long, genu recurvatum (“back knee”) can occur. A balance should be obtained such that the extension at the knee is sufficient to stabilize the knee in extension yet prevent genu recurvatum. If too much dorsiflexion is permitted by the anterior stop, there will be too much knee flexion during gait from midstance to toe-off.

Dorsiflexion Assist (Posterior Spring)

The posterior spring (see Figure 15-6) serves two purposes. It substitutes for concentric contraction of dorsiflexors to prevent flaccid foot drop after toe-off. It also substitutes (inadequately) for the eccentric activation of the dorsiflexors after heel strike.

The posterior spring prevents rapid plantar flexion at heel strike during its compression in the posterior channel. The posterior spring is again compressed during plantar flexion during late stance before toe-off. The posterior spring assists with toe clearance during the swing phase of gait by providing a downward thrust posterior to the ankle joint at toe-off, which results in dorsiflexion anterior to the ankle joint. The longer the channel, the greater the ability to control dorsiflexion.

A summary of some of the common indications for the various channel components is found in Table 15-1.

Metal Ankle-Foot Orthoses Varus-Valgus Control

Varus and valgus deformities are associated with rotation at the subtalar joint. A T strap is attached along the side of the shoe distal to the subtalar joint to help minimize the deformity (see Figure 15-6). T straps are also used to help prevent worsening of the deformity. T straps also help distribute pressure properly along the foot during weight-bearing.

T straps are referred to as being either medial or lateral. A lateral T strap is sewn to the lateral aspect of the shoe, and the belt is cinched around the medial upright of the AFO (see Figure 15-6). A lateral T strap is used to control a varus deformity. The belt is secured with a buckle around the medial upright. This helps create a force directing the subtalar joint outward, which counteracts the supination and adduction tendency that would result in excess varus. The opposite is true for a valgus deformity with the T strap being medially located. A pressure ulcer can develop over the malleolus if the T strap is buckled too tightly.

The T strap inadequately substitutes for the foot pronators, supinators, abductors, and adductors because it does not have an attachment on the plantar surface of the foot to create the mechanical advantage offered by the plantar-attached tendons.

Plastic Ankle-Foot Orthoses

Plastic AFOs are the most commonly used AFOs because of their cost, cosmesis, light weight, interchangeability with shoes, ability to control varus and valgus deformities, provision of better foot support with the customized foot portion, and ability to achieve what is offered by the metal AFO (Figure 15-13). Energy consumption is equal with a plastic solid AFO or a metal double-upright AFO.³ Although a plastic orthosis weighs less than its metal counterpart, the weight of the orthosis is not as important as the influence of the ground reactive force created by the presence of the orthosis. The same orthotic principles apply to orthoses made of plastic or metal. The effect of the plastic AFO on knee stability should be recognized. The plastic AFO prescribed for toe clearance should be just rigid enough to provide resistance for toe clearance. Excessive resistance to plantar flexion can make the knee unstable (create a flexion moment) after heel strike.²¹

FIGURE 15-13 Custom plastic solid (i.e., no ankle joint although still flexible) ankle-foot orthosis (AFO) with posterior trim line to allow some flexibility with plantar flexion. This is the most commonly prescribed AFO for foot drop. It is also referred to as a posterior leaf spring AFO, and it is usually set in a few degrees of dorsiflexion.

Plastic AFOs can be prefabricated or custom made. The reasons for prescribing a custom-molded orthosis include long-term need, conformed molding for comfort or insensate feet, placement of the orthosis in a fixed amount of plantar or dorsiflexion, better control of rotational deformities, and further reduction of weight-bearing for a tibial fracture or diabetic plantar ulcer. The custom process is similar to that previously described in this chapter for foot orthoses, with the positive mold serving as the model for the orthosis.

Some practical advice should be offered to the patient regarding the use of a plastic AFO. If changing shoes, it is best to have another pair with a similar heel height, to prevent altering the biomechanical effects at the foot, ankle, and knee. Tennis shoes are most accommodating for donning and doffing of the AFO. However, if dress shoes are to be worn, patients should also be told that their shoe size might need to be one-half size greater and the next width larger to accommodate the orthosis. A Blucher-style dress shoe with its open tongue helps accommodate the orthosis (see Figure 15-1).

Plastic Ankle-Foot Orthosis Components

The foot component of the AFO should extend beyond the metatarsal heads. The footplate can be extended beyond the toes to reduce spasticity aggravated by toe flexion. The shape and molding of the foot portion influence the biomechanics of more proximal joints.

The ankle and subtalar joints can be made more stable under four circumstances: (1) extend the trim line more anteriorly at the ankle level (a trim line is the anterior border of the plastic AFO); (2) make the plastic material thicker; (3) place carbon inserts along the medial and lateral aspects of the ankle joint; and (4) incorporate corrugations within the posterior leaf of the AFO. The strength of the AFO should be matched to the patient’s weight and activity level.

Plastic AFOs can also be hinged at the ankle. Ankle hinges allow full or partial ankle motion, which can permit a more natural gait. They should be considered when complete restriction of ankle motion is not required. Plastic ankle joints are light and are a good choice for children. Metal ankle joints are preferred for adults, particularly heavy adults. Newer designs have a single midline posterior pin or spring mechanism (Figure 15-14). This midline spring functions like the more traditional medial and lateral dual posterior spring assist mechanism (see Figures 15-8 and 15-9). This makes the AFO narrower in the mediolateral direction and slightly longer in the anterior-posterior direction, which better conforms to the design of most pants. Hinging an AFO adds mediolateral stability. Consider prescribing a hinged AFO for a patient with spasticity with a tendency toward inversion, or for a patient with multiplanar ankle and subtalar flaccidity accompanying a foot drop with a history of twisting the ankle.

FIGURE 15-14 Midline posterior stop articulated ankle-foot orthosis. Note the use of a plastic ankle joint to further decrease weight. Plastic ankle joints are more common in children (lightweight individuals). The use of a plantar stop with ankle joints is recommended for an active lightweight patient with plantar spasticity (e.g., a child with cerebral palsy).

The leg component should encompass three quarters of the leg and should be padded along its internal surface.¹¹ The proximal extent should end 1 inch below the fibular neck to prevent a compressive common peroneal nerve palsy.

The Solid Plastic Ankle-Foot Orthosis

The solid plastic AFO is the most commonly prescribed plastic AFO (see Figure 15-13). It can be made to serve several purposes. The term solid refers to an AFO that is made of a single piece of plastic. It does not have ankle joints. A solid AFO can still be flexible enough to allow some ankle motion, and it should be flexible with a posterior trim line for the treatment of foot drop without mediolateral instability. A solid AFO should be truly solid (not flexible) for the treatment of some cases of plantar spasticity.

Solid AFOs set at 90 degrees are commonly used for foot drop. Less obvious but equally important is the ability of the solid AFO to treat conditions affecting the knee. Again, it should be remembered that plantar flexion creates knee extension, and dorsiflexion creates knee flexion at heel strike. The AFO can be fixed in a few degrees of plantar flexion to provide stability at the knee during the stance phase of gait. Genu recurvatum can also be treated with a solid AFO. The more rigid the AFO, the greater the flexion moment at the knee at heel strike, which helps reverse the extension moment at the knee associated with genu recurvatum. The flexion moment at the knee also becomes even greater during midstance if the ankle is placed in a few degrees of dorsiflexion. Table 15-2 summarizes the important orthotic factors involved in creating knee extension and flexion moments throughout the gait cycle.

Table 15-2 Orthotic Componentry With Knee Flexion and Extension Moments

Knee Extension Moment/Stability	Knee Flexion Moment/Instability
Cushioned heel	Solid heel
AFO fixed in plantar flexion	AFO fixed in dorsiflexion
Posterior trim line on AFO (flexible)	Anterior trim line on AFO
Posterior offset knee joint	—

AFO, Ankle-foot orthosis.

Plastic Ankle-Foot Orthosis Varus-Valgus Control

The goal of orthotic intervention is to alter the ground reactive forces with custom molding to help maintain proper alignment of the lower limb by “building up” selected portions of the AFO. A three-point system is used to provide the counter forces necessary to oppose the forces of the deformity (Figure 15-15).^27,30 Some orthotists think that an orthosis should be firm (“not conforming”) to control a deformity. Pressure points should be present in expected areas at follow-up visits if the orthosis is serving its purpose. A custom ground reaction orthosis provides appropriate foot support that influences the rotation of more proximal joints (Figure 15-16). The anterior tibial shell closing helps stabilize the knee during gait (see Figure 15-11).

FIGURE 15-15 Three-point system control of equinovarus deformity. A, Control of varus rotational component at the foot (stars) and subtalar joint (dots)B, Control of equinus deformity.

(Modified from Marx HW: Lower limb orthotic designs for the spastic hemiplegic patient, Orthot Prosthet 28:14, 1974.)

FIGURE 15-16 Oregon Orthotic System rotational control ankle-foot orthosis. Note the corrugations that add strength to the orthosis. Also note the metal ankle joint that is similar to those in Figure 15-10.

(Courtesy Oregon Orthotic System, Albany, OR.)

An equinovarus (or inversion) deformity is controlled by applying forces medially at the metatarsal head area and calcaneus. The next force is applied more proximally along the lateral aspect of the fibula. This helps prevent inversion at the subtalar and ankle joints. A more proximal medial tibial force is applied to provide stabilization of the leg portion of the plastic AFO by providing an opposing force to the fibular area (see Figure 15-15). A three-point system also exists at the foot level to help prevent supination of the foot related to the equinovarus deformity (see Figure 15-15). A three-point system is again applied to control the plantar flexion deformity associated with equinovarus (see Figure 15-15).

The reverse of the above described three-point system to control varus can be used to control valgus at the foot. Movements in all joints should be considered when prescribing an orthosis.

Patellar Tendon–Bearing Ankle-Foot Orthoses

A patellar tendon–bearing (PTB) AFO uses the patellar tendon and the tibial condyles to partially relieve weight-bearing stress on skeletal structures distally, with more weight-bearing distributed along the medial tibial condyle.²⁵ PTB is a misnomer for this orthosis because only about 10% of the weight is distributed along the patellar tendon and the medial tibial condyle. Most of the weight-bearing is distributed throughout the soft tissues of the leg that are compressed by an appropriately fitted orthosis. Compression of the soft tissues of the leg is also responsible for maintaining alignment and length of the tibia after a fracture.^45,46

PTB AFOs are often prescribed for diabetic ulcerations of the foot, tibial fractures, and relief of the weight-bearing surface in painful heel conditions such as calcaneal fractures, postoperative ankle fusions, and avascular necrosis of the foot or ankle. The orthoses are made of plastic and are bivalved. They fit snugly with the use of Velcro straps (Figure 15-17) or buckles similar to those of ski boots. A custom-molded PTB AFO can reduce weight-bearing in the affected foot by up to 50%.

FIGURE 15-17 Custom bivalved patellar tendon–bearing ankle-foot orthosis. Ten percent of the weight is transferred to the patellar tendon. Fifty percent weight-bearing reduction is achieved by custom-fitted contact distributed throughout the leg. This was prescribed for a young girl after resection of a large, benign tumor of the left tibia.

Custom-made PTB AFOs are indicated when maximum weight-bearing reduction is necessary to ensure proper healing (such as in a debrided diabetic heel ulcer) and reduction of pain. It should first be determined that the painful condition is associated with weight-bearing rather than with range of motion. If pain occurs with range of motion, then the pain-producing range of motion should be eliminated.

The solid plastic orthosis makes contact with the ground before the reactive force is absorbed significantly by the foot, and then distributes this force more proximally along the leg. Compared with a prefabricated AFO, a custom-made PTB AFO more effectively distributes pressure over a greater surface contact area for maximal weight-bearing reduction.

Pressure Relief Ankle-Foot Orthoses

A pressure relief AFO is also known by its acronym, PRAFO (Figure 15-18). This type of AFO has different brand names depending on the company that furnished it, including PRAFO, Multi-podus AFO, and Lennard AFO. This orthosis serves two purposes: pressure relief and contracture prevention. Pressure relief is achieved at the heel by completely eliminating weight-bearing with the heel cut out, and also by using a hinged lever arm posteriorly that can be adjusted medially or laterally to prevent medial or lateral malleolar pressure sore development. This should be applied on the immobilized or motionless affected lower limb at all times while in bed. A PRAFO is frequently used in demented patients with hip fractures who do not have much lower limb mobility, as well as in patients with a stroke who have dense hemiplegia. Plantar flexion contracture prevention occurs by keeping the ankle joint in a neutral position while the AFO is donned.

FIGURE 15-18 Pressure relief ankle-foot orthosis (PRAFO). The heel cutout provides complete heel pressure relief. The hinged posterior lever arm prevents ankle pressure sore development either medially or laterally and can be adjusted like a windshield wiper as necessary to prevent medial or lateral malleolar pressure.

Common Ankle-Foot Orthosis Prescriptions

The three most common physiatric AFO prescriptions are those for foot drop, plantar spasticity, and lumbar spinal cord injury (Figure 15-19). The most common AFO prescription for foot drop is a custom nonhinged plastic AFO set in a few degrees of dorsiflexion with a posterior trim line. This is also referred to as a posterior leaf spring AFO. The few degrees of dorsiflexion ensures foot clearance during the swing phase of gait. It also helps the ankle “spring” into dorsiflexion after the foot is lifted off the ground in a plantar-flexed position from push-off. The minimal weight and bulk of this AFO are highly desired by the patient with foot drop. The avoidance of hinging not only minimizes bulk, but from a practical standpoint it keeps the mediolateral dimension of the AFO narrow to best accommodate a variety of shoes and pants. If there is significant subtalar joint instability (e.g., a patient with a history of inversion injuries and falling), a hinged plastic AFO with metal double-action ankle joints (see Figure 15-10) with springs in the posterior channels (dorsi-assist) would provide mediolateral stability yet also permit plantar flexion. Alternatively, a hinged midline posterior stop AFO that is spring-loaded (see Figure 15-14) can also provide mediolateral stability for the patient with foot drop.

FIGURE 15-19 Common ankle-foot orthosis (AFO) prescriptions. (A) Foot drop AFO. (B) Plantar spasticity AFO. (C) Lumbar spinal cord injury AFO.

The most common AFO prescription for plantar spasticity is either a hinged custom plastic AFO with a single midline posterior stop or a hinged custom plastic AFO with pins in the posterior channels to provide plantar stop at 90 degrees. The former is more likely to be considered in milder cases of spasticity without a significant inversion deformity. The latter is more likely to be considered if a significant inversion deformity is still present after all other medical treatment measures to manage the spasticity have been exhausted. Metal ankle joints with posterior pins in this case would provide better mediolateral support yet still permit some dorsiflexion with the anterior channels left open. Permitting dorsiflexion allows a more normalized gait and provides a therapeutic stretch to the plantar flexors from midstance to toe-off during gait. Recent research studies support the use of hinged AFOs with plantar stops at neutral (90 degrees) as a preferred AFO for an active pediatric population with lower limb spasticity.^{37,40,49,53,54}

The most common lumbar spinal cord injury AFO prescription is bilateral custom plastic ground reaction (anterior tibial shell closing) AFOs fixed in 10 degrees of plantar flexion. The anterior tibial shell closing and 10 degrees of plantar flexion both help create knee extension moments with weight-bearing to add stability to the knees during ambulation. A walker or bilateral Lofstrand forearm orthoses are still needed to permit ambulation.

Checkout

The patient should be examined after fitting and use of the orthosis. The first and most obvious form of a checkout is to verify that the gait pattern is improved with the orthosis in comparison to without the orthosis. The orthotic ankle joint should coincide with the tip of the medial malleolus. The patient is to be checked for ease of donning and doffing the orthosis, and while it is off, observed for areas of skin breakdown. If the AFO was prescribed to control spasticity, the orthotic evaluation should include determining its effectiveness in a dynamic setting, because spasticity can worsen with ambulation. In cases where significant deformity is being addressed with orthotic intervention, some redness can and should be present if the orthosis is doing its job. Some redness is acceptable as long as it is dispersed in as large an area as possible and as long as there is no skin breakdown.

Knee Joints

There are three basic types of knee joints. The straight-set knee joint provides rotation about a single axis (Figure 15-20). It allows free flexion but prevents hyperextension. It is often used in combination with a drop lock, which keeps the knee in extension throughout all phases of gait for further stability.

FIGURE 15-20 Straight-set knee with drop lock.

The polycentric knee joint uses a double-axis system to simulate the flexion-extension movements of the femur and tibia at the knee joint (Figure 15-21). Although this concept is theoretically sound, the polycentric knee joint has not proved to be advantageous over the straight-set knee joint, and it is less commonly used. It also adds bulk to the orthosis. It is most frequently used in sport knee orthoses.

FIGURE 15-21 Polycentric knee joint.

The third type of knee joint is the posterior offset knee joint (Figures 15-22 and 15-23; see Table 15-2). It is prescribed for patients with weak knee extensors and some hip extensor strength. It allows free flexion and extension of the knee during the swing phase of gait and helps keep the orthotic ground reactive force in front of the knee axis for stability during stance. The center of gravity is normally posterior to the knee at heel strike, creating a flexion moment at the knee, which requires quadriceps and hamstring muscle contraction to counteract this force. The posterior offset knee joint component of the KAFO helps place the ground reactive force anterior to the orthotic knee joint, creating an extension moment at the knee during stance to compensate for the weak knee extensors. The posterior offset knee joint should have a hyperextension stop to help prevent genu recurvatum.

FIGURE 15-22 Posterior offset knee joint.

FIGURE 15-23 Ground reaction force (GRF) schematic drawing. The arrows depicted poining upward from the ground are representative of the GRF. The knee joint remains extended (e.g., stable) if the GRF is anterior to the knee. A knee flexion moment is created if the GRF is posterior to the knee. (A) GRF at stance. (B) GRF at heel strike. (C) Orthotic GRF at heel strike with posterior offset orthotic knee joint. A solid heel also moves the GRF posteriorly (i.e., knee flexion moment/instability) and a soft heel moves the GRF anteriorly (i.e., knee extension moment/stability).

Occasionally the offset knee joint does not provide adequate stability at the knee. The ankle component of the KAFO can then be set in 10 to 15 degrees of plantar flexion to further help create an extension moment at the knee for stability. Lastly, if these measures are insufficient at providing knee stability, the posterior offset knee joints can be locked in extension with drop locks (see Figure 15-20).

Knee Locks

Knee locks are used to provide complete stability at the knee. There are four common types of knee locks; these are discussed in order of their frequency of use, beginning with the most commonly used.

The ratchet lock has recently become the most commonly prescribed knee lock (Figure 15-24). The ratchet lock has a catching mechanism that operates in 12-degree increments. As the user rises from a seated to a standing position, if there is a tendency for the knee to become unstable and flex, the ratchet lock prevents that movement and keeps the gains made toward extension. Once the patient is standing with the knees extended, knee flexion is achieved by pressing down on either a release lever or by sliding the locking mechanism.

FIGURE 15-24 Ratchet lock. The 12-degree increments gained with knee extension prevent the knee from going into flexion, thereby adding stability and a safety factor as one rises from a seated to a standing position. The mechanism is released by using the lever arm to allow one to resume a seated position.

Before the development of the ratchet lock, the drop lock (ring lock) was used most commonly in both the medial and lateral uprights of the KAFO (see Figure 15-20). Its advantage is simplicity of design without bulk. However, fine motor coordination skills are needed to lock the knee in complete extension. In addition, there are two locks per side yet only two hands. The drop lock also can “settle” after ambulation and might be difficult to pull up to unlock the knee. The disadvantage of the drop lock in comparison with the ratchet lock is that there is no locking mechanism until full knee extension is obtained. Consequently a patient’s knee can collapse into flexion when it is not sufficiently extended to activate the drop lock. A collapse into flexion does not occur with the ratchet lock, and so the patient is less likely to fall. A drop lock can be used unilaterally along the lateral upright if the patient is relatively lightweight and has a low activity level.

The bail lock (also known as the Swiss, French, Schweitzer, or pawl lock) provides the easiest method of simultaneously unlocking the medial and lateral knee joints of a KAFO (Figures 15-25 and 15-26). Two hands can be used for two bail locks, whereas there are a total of four ratchet locks or four drop locks with other bilateral KAFOs. Lifting up the bail posteriorly releases the knee joint to permit flexion, allowing the patient to sit down. The patient can also alternatively catch the bail on the edge of a chair by leaning back to release the lock mechanism to permit sitting. The locking mechanism is spring-loaded to assist locking the knee into extension (see Figure 15-26). The bail is often padded with rubber to protect the clothing from being torn or soiled. The KAFO with a bail lock can be worn over or under clothes, depending on the size of the bail lock and the size of the clothing. On its downside, child cruelty can lead to one child kneeing the handicapped child’s knee from behind and, with this type of lock, causing the child to fall—not a good practical joke.

FIGURE 15-25 Padded spring-loaded bail lock.

(Courtesy Becker Orthopedic Co, Troy, MI.)

FIGURE 15-26 Spring-loaded bail lock mechanism. Lifting the bail permits free flexion for sitting, and the spring mechanism helps lock the knee joint into extension.

The dial lock (formerly known as a turn buckle) is used to stabilize the knee in varying amounts of flexion (Figure 15-27). It can be adjusted in 6-degree increments and is more precise for the management of a knee with a flexion contracture than a KAFO with ratchet locks. Its uses include helping prevent progression of a flexion contracture or assisting with the gradual reduction of a flexion contracture.

FIGURE 15-27 The dial lock may be adjusted every 6 degrees for precise control of knee flexion.

The Thigh Component of a Knee-Ankle-Foot Orthosis

The thigh band needs to be wide enough to adequately distribute the pressure of the ground reactive force transmitted through the knee axis. A partial plastic thigh shell can provide a greater contact area and decrease high-pressure areas if properly fitted. Plastic-metal combination KAFOs also decrease the weight of the KAFO, which can increase patient comfort and usage. A low thigh band is used to prevent genu recurvatum.

Scott-Craig Orthosis

The Scott-Craig orthosis (Figure 15-28) was designed to provide the patient with paraplegia who has a complete lesion at L1 or higher, with a more functional and comfortable gait.⁴⁷ It was also designed to reduce unnecessary hardware, to be a KAFO of lighter weight, and to be easy to don and doff. This orthosis was named after an orthotist, Bruce Scott, who worked at Craig Hospital in Englewood, Colorado.

FIGURE 15-28 Scott-Craig knee-ankle-foot orthosis.

(Courtesy Becker Orthopedic Co, Troy, MI.)

The orthotic design consists of an ankle joint with anterior (permits 5 degrees of dorsiflexion to simulate plantar flexion) and posterior (set at 90 degrees to prevent toe drag) pin stops, a sole plate extending to the metatarsal heads, a crossbar added to the metatarsal head area for mediolateral stabilization, and an offset knee joint with a bail lock.⁴⁷ A rigid anterior tibial band is positioned directly below the tibial tubercle. A rigid proximal thigh band is positioned posteriorly and is closed anteriorly with a soft strap secured with Velcro. These two bands should be shallow enough to hold the knee in extension. A three-point system helps keep the knee in extension by applying pressure at the proximal thigh posteriorly, the proximal tibia anteriorly, and at the calcaneus posteriorly.²² The ankle joint functions with a dorsiflexion stop used to simulate the triceps surae function as previously described, and with a posterior stop set at 90 degrees to prevent toe drag.

A group headed by Lehmann²⁴ analyzed the Scott-Craig orthosis and found that it was the easiest of the KAFOs tested to don and doff. The original design of this orthosis is still being prescribed for patients with paraplegia.

Swedish Knee Cage

The knee orthosis (KO) known as a Swedish knee cage (Figure 15-29) is used to control minor to moderate genu recurvatum caused by ligamentous or capsular laxity. This articulated KO permits full knee flexion and prevents hyperextension. The Swedish knee cage uses a classic three-point orthotic system with two bands placed anterior to the knee axis (one above and one below the knee) and a third band posterior to the knee joint in the popliteal area. It also has an additional thigh band with longer uprights to obtain better leverage at the knee joint. Severe genu recurvatum might need to be controlled with longer lever arms, such as that offered by a KAFO.

FIGURE 15-29 The articulated Swedish knee cage, which uses a three-point system to control genu recurvatum.

Genu recurvatum can also be controlled through additional orthotic measures, including a solid plastic AFO that resists plantar flexion. This can be used in cases where pathology also affects the ankle or subtalar joints. The more rigid the AFO, the greater the flexion moment at the knee during heel strike (which counters the extension moment of a knee with recurvatum). A shoe with a solid heel also helps create a greater knee flexion moment, which is preferred in this case over a shoe with a cushioned heel, which would facilitate a knee flexion moment. An additional flexion moment at the knee during midstance can be obtained by fixing the AFO in a few degrees of dorsiflexion.

Osteoarthritis Knee Orthoses

The same orthotic three-point principle that has been applied for years in the Swedish knee cage for genu recurvatum has recently also been applied to osteoarthritis of the knee, most commonly with medial compartment narrowing (Figure 15-30). The three-point system distribution is achieved by a strap that is applied across the knee joint. In one study, 19 of 20 patients with varying degrees of osteoarthritis experienced significant relief of knee pain.²⁷ Radiographic improvement in joint alignment was also noted. The limiting factor regarding this knee orthotic prescription is the patient’s weight. A morbidly obese patient with an abundance of fatty tissue around the knee will not support the KO adequately. In such cases where this KO and surgery are precluded, the foot orthoses with lateral buildup as described earlier in this chapter should be considered. The foot orthosis with a lateral buildup is considered the preferred first-line orthotic treatment for osteoarthritis of the knee. (See Osteoarthritis of the Knee in the Foot Orthoses section.)

FIGURE 15-30 The Generation II knee orthosis for tricompartmental osteoarthritis of the knee. This uses the standard orthotic three-point distribution system in a medial-lateral distribution rather than in an anterior-posterior distribution as was noted with the Swedish knee cage (see Figure 15-29).

Sport Knee Orthoses

There is an increasing abundance of sport orthoses on the market. There is also a lack of definitive research regarding their role in sports. This can lead to much confusion regarding their prescription, unless the KO is reviewed systematically. Sport KOs can be divided into prophylactic, rehabilitative, and functional categories.³¹

Prophylactic knee bracing attempts to prevent or reduce the severity of knee injuries. There is currently no evidence to support the use or cost benefit of these orthoses. Some studies have found that the use of these orthoses actually increased the number of athletes with knee injuries.^44,52 It is theorized that knee-braced players can put themselves in compromising positions because of overreliance on the orthosis and that this can contribute directly to the increasing injury rates observed. The use of prophylactic knee bracing has also been associated with increased energy consumption, which can impair athletic performance.¹³

Rehabilitative knee bracing is used to allow protected motion within defined limits.³⁶ It is useful for postoperative and conservative management of knee injuries, and is most commonly applied postoperatively for anterior cruciate ligament–reconstructed knees (Figure 15-31) and patellofemoral pain syndrome.^∗

FIGURE 15-31 Fusion anterior cruciate ligament knee orthosis. This type of lightweight knee orthosis is designed to prevent hyperextension and also offer mediolateral stability at the knee. It may also offer some proprioceptive feedback.

(Courtesy BREG, Inc, Vista, CA, and Elizur Corp, Pittsburgh, PA.)

Functional knee bracing is designed to assist or provide stability for the unstable knee. Functional knee bracing does not replace the need for rehabilitation of the knee. Knee braces are used most commonly to stabilize a laterally subluxing patella^7,28 or an anterior cruciate ligament–deficient knee.^2,32,51 Their use has been shown to be effective only at loads much lower than those placed on the knee during athletic participation. In summary, functional knee bracing can possibly play a role in the treatment of pathologic laxity by possibly decreasing the frequency of unstable episodes.³⁶

Caster Cart

The disabled child should identify early with motion so that ambulatory skills can progress naturally.¹ Without familiarity with motion, disabled children lack the desire to ambulate once placed in a parapodium or reciprocating gait orthosis.

The caster cart (Figure 15-32) is used for children with a developmental delay in ambulatory skills, and it serves as an initial mobility aid. It is most often prescribed for children with spina bifida. Most children are upright and cruising by 10 months.¹⁴ Children with paraplegia should be fitted for a caster cart once they have obtained enough upper limb strength and trunk balance to propel themselves. If balance is a problem for the child, a deep seat bucket can be prescribed to help provide balance so that the child can use the upper limbs for propulsion.

FIGURE 15-32 Caster cart. This is an initial mobility aid for the disabled child. The child uses it as a “prewheelchair device” for mobility.

The caster wheel at the back of the cart facilitates multidirectional movement. Initially the child can be pushed around in the cart with a handle attached posteriorly so that the cart serves as a stroller.

Standing Frame

The use of a standing frame (Figure 15-33) typically follows successful use of a caster cart. The age range for initial use is usually 8 to 15 months. Children can continue to use their caster carts during this time. Children who are pulling themselves up along furniture are typically ready for a standing frame. This is the first sign that they are interested in standing and moving.¹⁴

FIGURE 15-33 A standing frame for initial upright activities. Used by children who desire to stand, as determined by attempts to pull themselves upright.

The standing frame helps balance the body in space and allows free use of the upper limbs for participation in activities. Children with thoracic level lesions need AFOs to provide good ankle and foot support in the standing frame or parapodium. Initial gait training can occur with the use of the standing frame via a swing-through gait with the assistance of parallel bars.

Parapodium

The parapodium was also referred to in the past as a swivel orthosis (Figure 15-34). Before children are given a parapodium, they should first demonstrate adequate use of a standing frame and exhibit a desire to ambulate. A child’s standing frame can be evaluated for wear and tear to determine whether it has been used sufficiently so that the child can advance to a parapodium. A frequently used standing frame (or any orthosis) will show evidence of wear and tear that includes soiling and scratches. It is important to note this, because parents frequently set expectations too high for the disabled child. A child who has not used a standing frame will likely be unable or unwilling to ambulate with a parapodium.

FIGURE 15-34 (A) Parapodium with hip and knee joints locked in extension. (B) Parapodium with hip and knee joints unlocked and in a flexed position.

(Courtesy Variety Ability Systems, Inc, Toronto, Ontario, Canada.)

A parapodium is an appropriate prescription for children who are unlikely to become functional walkers because of the severity of their impairment. It often complements wheelchair use.²⁶ It is most commonly prescribed for children between 2.5 to 5 years of age.

A parapodium allows crutchless gait. Ambulation occurs by the child pivoting the hips and using “body English” to swivel one side of the oval-based stand forward and then repeating the same event for the other side. Its design is similar to the standing frame, but it has hip and knee joints. The hip and knee joints remain locked in extension to permit ambulation in the upright position but can be unlocked (simultaneously in some models) to permit sitting. The difficulties experienced with the use of this orthosis include donning and doffing and rising from a seated position to a standing position.

Reciprocating Gait Orthosis

The reciprocating gait orthosis (RGO) was formerly known as a hip-guided orthosis (Figure 15-35). It can also be referred to as a bilateral hip-knee-ankle-foot orthosis (HKAFO). The purpose of the RGO is to provide contralateral hip extension with ipsilateral hip flexion. The RGO is appropriate for children who have used the standing frame, developed good trunk control and coordination, can safely stand, and are mentally prepared for ambulation. Good upper limb strength, trunk balance, and active hip flexion are important positive variables for ambulation.¹² Obesity, advanced age, lack of patient or family motivation, scoliosis, spasticity,⁸ and contractures are significant negative factors in the long-term use of the RGO. This type of orthosis clearly only complements the use of a wheelchair for mobility purposes and serves therapeutic purposes of exercise and upright activities. One newer type of spinal cord injury orthosis is the Walkabout which has a scissoring mechanism in the groin area attaching two KAFOs via a hinge. The trade-off with this device is a lack of contralateral hip extension with ipsilateral hip flexion for a less bulky orthosis to don and doff.³⁴

FIGURE 15-35 Isocentric reciprocating gait orthosis.

(Courtesy Center for Orthotic Design, Redwood City, Calif, and Fillauer Companies, Inc, Chattanooga, TN.)

The neurologic level of spinal cord injury is not a very reliable predictor of ambulation capability for children. As children with spinal cord injuries grow taller, they might experience more difficulty walking as their center of gravity becomes lower.

The RGO is prescribed most commonly for children aged 3 to 6 years. The concept of the RGO was developed by researchers working with a patient who had active hip flexion and no hip extension. Gait is initiated with unilateral hip flexion and can be assisted by swaying the trunk when hip flexion is inadequate. This type of gait pattern can also be considered to be a form of physical therapy, because hip extension occurs passively with each step, helping to reduce flexion contractures. Cables were initially used to provide the necessary hip motion, but newer mechanical methods of reciprocal gait use a “teeter-totter” concept (see Figure 15-35). This type of RGO has been reported to be more energy efficient than an RGO with cables.⁶⁰

Crutches are used with the RGO to provide a control mechanism, taking advantage of the forward momentum to produce small propulsive forces when needed.²⁹ This also is a disadvantage of this orthosis (compared with the parapodium) because the upper limbs are not free for other activities. The patient with an RGO is able to negotiate a greater variety of surfaces than would be possible with the parapodium.⁴³

The hip joints of the RGO have hip flexion and abduction capabilities on release of the locking mechanisms. It is recommended that one hip joint have abduction capability to permit catheterization and to allow sitting in a hip-flexed and abducted position.

Canes

To prescribe a cane:

The elbow should be flexed approximately 20 degrees, which is a desirable elbow position for all ambulation aids. Canes are made of wood or aluminum, with the aluminum alloy cane having adjustable notches so that “one cane fits all.”

There are three common types of canes (see Figure 15-36). The C cane is most commonly used. It is also known as a crook top cane or a J cane. A functional grip cane offers the patient a grip that can be more comfortable than with the C cane. A quad cane provides an increased area of support compared with the other canes. Quad canes also come in narrow- and wide-based forms for different degrees of support. The lateral two legs are directed away from the body.

A cane is used on the side opposite the supporting lower limb. It is advanced with the opposite lower limb. It is usually held on the patient’s unaffected side. This can be done to lessen the force exerted on a hip with pathology. The load is increased by four times the body weight on the stance side during gait because of the gravitational forces and the gluteus medius–gluteus minimus force exerted across the weight-bearing hip.⁵ The cane helps decrease the force generated across the affected hip joint by decreasing the work of the gluteus medius-minimus complex. This occurs when the upper limb exerts force on the cane to help minimize pelvic drop on the side opposite the weight-bearing lower limb.

Patients should be instructed on how to ascend and descend stairs. The pneumonic “up with the good and down with the bad” serves as an easy reminder. The patient should always have the “good” lower limb assume the first full weight-bearing step on level surfaces.

Walker

To prescribe a walker:

A walker provides maximum support for the patient but also necessitates a slow gait. It is useful for hemiplegic and ataxic patients. Wheels can be added to the front legs to facilitate movement of the walker for those who lack coordination in the upper limbs. Patients using wheeled models should be supervised initially to ensure safety. Some walkers also have a front U-shaped extension with extra supports to provide stability for stair climbing. A patient needs to be motivated and have good strength and coordination to use this model of walker.

Visual Impairment Cane

To prescribe a visual impairment cane:

A visual impairment cane should be lightweight, flexible, and easily collapsible. The distal inches of the cane are red. Please also note the following additional physiatric visual impairment pearl for elevator rides: two dings is “down” and one ding is “up.”

Crutches

To prescribe crutches:

A crutch is defined as a device that provides support from the axilla to the floor. Although there are different types of crutches and canes, they can all be referred to as orthoses because they are applied to the external surface of the body to improve function.

The patient should be able to raise the body 1 to 2 inches by complete elbow extension. Despite the popularity of padding the axillary area of the crutch, this should not be done. It needs to be emphasized to the patient that crutches are not designed to be rests for body support. This point should be made to the patient to reduce the incidence of compressive radial neuropathies or plexopathies.

Nonaxillary Crutches

Nonaxillary crutches are more appropriately called forearm or arm canes, or forearm or arm orthoses. The Loftstrand forearm orthosis, Kenny sticks, the Everett or Warm Spring orthosis, the Canadian crutch, and the platform forearm orthosis will be discussed (see Figures 15-36 and 15-37).

Lofstrand Forearm Orthosis

To prescribe a Lofstrand forearm orthosis:

The proximal portion of the orthosis is also angled at 20 degrees to provide for a comfortable, stable fit. It is often made of tubular aluminum. It provides less support than crutches for ambulation, but is sufficient for many patients. Lofstrand forearm orthoses are most often used bilaterally. The open end of the cuff is placed on the lateral aspect of the forearm to permit elbow flexion and grasping without dropping the orthoses. The advantages of this orthosis are that it is shorter than an axillary crutch, and the forearm cuff pivots to allow the patient to lean on the crutch for hand activities.

Wooden Forearm Orthosis (Kenny Stick)

Another forearm orthosis option is the Kenny stick (see Figure 15-37). It was named after Sister Kenny, who sawed off the top half of wooden crutches and placed a leather band around the proximal portion of the forearm. It was designed for polio patients who had satisfactory proximal upper limb musculature but were weak distally and unable to effectively hold and control the orthosis. Its advantage over the Loftstrand orthosis is the presence of a closed leather band. This assures patients (more so than the Lofstrand forearm orthosis does) that they will not drop the ambulation aid.

Platform Forearm Orthosis

To prescribe a platform forearm orthosis:

This orthosis is helpful for patients with painful wrist and hand conditions, as well as for those with elbow contractures. Velcro straps are applied around the forearm, especially for patients with weak hand grips.

Triceps Weakness Orthoses (Arm Orthoses)

These orthoses, also known as triceps weakness crutches, were originally developed for patients with poliomyelitis. The metal version is known as a Warm Spring crutch or Everett crutch. The wooden version is known as a Canadian crutch. These crutches resemble the “axillary” crutches in style, but end proximally with a cuff at the midarm level. These ambulation aids help prevent flexion (buckling) of the elbow during gait.

Crutch Tips and Hand Grips

The purpose of crutch tips is to absorb shock and prevent slippage. Crutches are only as safe as the quality of their crutch tips. Special crutch tips are available for rainy and icy conditions (Figure 15-38). At each checkup the physician should make sure that the crutch tips are not worn out. Hand grips are used to reduce pressure on the hands and are also safety features because they help prevent slippage.

FIGURE 15-38 A, Snow Boot crutch tip for use in snowy and icy conditions. B, Rain Guard crutch tip for use in wet conditions.

(Courtesy Hi-Trac Industries, Holley, MI.)